Calcuculus problem

Where did I go wrong?

Okay, it's proving the integral of x.

x.dx = 1/2.x^2
2x.dx = x^2
x = x^2/2.dx
1 = x/2.dx
1/x = 1/2.dx
2.dx = x
2x = x
2 = 1

Oh shi...!

Someone help?

Originally posted by lord xyz
Where did I go wrong?

Okay, it's proving the integral of x.

x.dx = 1/2.x^2
2x.dx = x^2
x = x^2/2.dx
1 = x/2.dx
1/x = 1/2.dx
2.dx = x
2x = x
2 = 1

Oh shi...!

Someone help?

Take the derivative of 1/2x^2 😄

Umm, what did you do with the dx?

Originally posted by Admiral Akbar
Take the derivative of 1/2x^2 😄

Umm, what did you do with the dx?

Ah **** it, 2 = 1.

here´s my calculus problem..

WTF is Calculus?

Originally posted by lord xyz
Where did I go wrong?

Okay, it's proving the integral of x.

x.dx = 1/2.x^2
2x.dx = x^2
x = x^2/2.dx
1 = x/2.dx
1/x = 1/2.dx
2.dx = x
2x = x
2 = 1

Oh shi...!

Someone help?

2x.dx = x^2
x = x^2/2.dx

Grammar problems to boot.

Originally posted by King Kandy
Your notation is so horribly confusing, that I can't hope to help you here. Especially in this step, I don't have a clue what exactly you're trying to communicate (taking the derivative of both sides?)

2x.dx = x^2
x = x^2/2.dx

2x = d(x^2)/dx

I think that's my first error.

I solved for d and got x = x when I subed...

maybe you need to collect all the x's on one side then sub in d=1/2

also, I am assuming the periods in the first equation are multiplication?

even when I collected the x's, I just keep getting x^2 - x^2 = 0

I haven't done calculus in over 5 years....

Originally posted by Bicnarok
here´s my calculus problem..

WTF is Calculus?

It's a part of the mathematical field of Analysis. In fact it's what the German mathematician Leibniz invented, but that prick Newton took credit for.

For the OP, first of all you forgot the constant every time you integrated, that's not good. Anyways lets try to note that a bit better:

1) Integral x = (x²/2)+C
You: x.dx = 1/2.x^2
2) Integral 2x = x² + C
You: 2x.dx = x^2
3) Integral of x²/2 = (x³/6) + C
Your: x = x^2/2.dx
Here you seem to say that the integral of x²/2 is x. That is however not the case. In step one we saw that the Integral of x is x²/2 however the opposite is not true. So that is the first mistake that breaks your whole process, I believe
4) -
You:1 = x/2.dx
You can't just multiply in and out of integrals that's not how they work. Even if x was the integral of x²/2 dividing by it would give you 1 = (1/x) times Integral x²/2, not Integral of x/2
5) -
You: 1/x = 1/2.dx
Same problem and continuing from a false premise.
6) -
2.dx = x
Same
7)-
2x = x
Here you suddenly remember the integral again though you disregarded it before. You also miss the constant again.
8) -
2 = 1
And that's why this is wrong.

I hope that helps give some clarity.

EDIT- Removed

Originally posted by Bardock42
It's a part of the mathematical field of Analysis. In fact it's what the German mathematician Leibniz invented, but that prick Newton took credit for.

For the OP, first of all you forgot the constant every time you integrated, that's not good. Anyways lets try to note that a bit better:

1) Integral x = (x²/2)+C
You: x.dx = 1/2.x^2
2) Integral 2x = x² + C
You: 2x.dx = x^2
3) Integral of x²/2 = (x³/6) + C
Your: x = x^2/2.dx
Here you seem to say that the integral of x²/2 is x.

Which I believe should've been written as d(x^2)/dx integration, see.

That is however not the case. In step one we saw that the Integral of x is x²/2 however the opposite is not true. So that is the first mistake that breaks your whole process, I believe
4) -
You:1 = x/2.dx
You can't just multiply in and out of integrals that's not how they work. Even if x was the integral of x²/2 dividing by it would give you 1 = (1/x) times Integral x²/2, not Integral of x/2
5) -
You: 1/x = 1/2.dx
Same problem and continuing from a false premise.
6) -
2.dx = x
Same
7)-
2x = x
Here you suddenly remember the integral again though you disregarded it before. You also miss the constant again.
8) -
2 = 1
And that's why this is wrong.

I hope that helps give some clarity.

Originally posted by lord xyz
No, that isn't (x^2/2)dx, I divided by dx.

Which I believe should've been written as d(x^2)/dx integration, see.

Yeah, I did forget the constant. My bad. [/B]

Ah okay, I see, well you can't do that. So I guess you found your answer. I'm still not sure about the thing King Kandy posted a while back though.

if bardock eats 6 donuts in 60 seconds outta the dozen and x is what's left in the box, what does x=?

hehe..

Originally posted by Bardock42
Ah okay, I see, well you can't do that. So I guess you found your answer. I'm still not sure about the thing King Kandy posted a while back though.

Originally posted by FistOfThe North
if bardock eats 6 donuts in 60 seconds outta the dozen and x is what's left in the box, what does x=?

hehe..

That's unsolvable. You gave a speed and an amount. We'll still need time to solve your equation.

Originally posted by Bardock42
That's unsolvable. You gave a speed and an amount. We'll still need time to solve your equation.

Well he said "in 60 seconds" not "per 60 seconds" so the answer should be 6.

Originally posted by Symmetric Chaos
Well he said "in 60 seconds" not "per 60 seconds" so the answer should be 6.

Well that still assumes that I stop after 60 seconds, or that it is counted after 60 seconds, which is not necessarily clear from the phrasing.

Ermm, bump? 🙂

I probably failed that question anyway. 😐

You can't just "divide" by dx, that's not an operation that makes any kind of sense.